The instant invention relates to finger operated switching apparatus and more particularly to such apparatus which is used by an operator to enter data into a computer, word processor, typewriter or the like.
A conventional typewriter keyboard includes several horizontal rows of keys oriented transversely to an operator. The conventional arrangement of letters on such a keyboard is sometimes referred to as the QWERTY format after the first six letters on the top row of letter keys. The QWERTY format was developed in the late 1800's and has remained the standard keyboard format to date for typewriters as well as for computers, word processors, and other data entry terminals.
The QWERTY format keyboard suffers from several disadvantages. Hand movement up and down the keyboard is required to position the fingers for striking keys at the upper and lower portions of the board. Even when it is not necessary to move the entire hand, substantial finger movement is required to move the finger between keys on adjacent rows or between adjacent keys on the same row. Such hand and finger movement decreases the rate at which an operator can enter data via the keyboard.
A number of prior art designs have attempted to improve upon the QWERTY format. For example, U.S. Pat. No. 4,584,443 to Yeager discloses a captive digit input device which includes a set of cups into which an operator's fingertips are received. Data is entered by depressing the cup along the axis of the finger and by pivoting the finger toward and away from the operator. Although the Yeager device reduces the amount of hand and finger travel required from that necessary on a QWERTY format keyboard, it suffers from several disadvantages. First, two of the data entry movements, pivoting a finger both toward and away from the operator, are awkward relative to other types of finger movements, e.g., finger extension and contraction. Secondly, the cups in the Yeager device must be custom-designed for users having different sized fingers.
U.S. Pat. No. 3,945,482 to Einbinder discloses orthogonal input keyboards in which multiple keys present horizontal and angled keyboard surfaces toward a single finger. The Einbinder keyboard design requires different keys to be differently shaped, thereby increasing the expense of manufacturing such a keyboard, and requires more finger travel to strike various keys than is desirable.
The finger operated switching apparatus of the invention comprises a key having a substantially horizontal switching axis and a substantially vertical switching axis. The key includes a horizontal surface over which the tip of an operator's finger may be positioned for applying downward force to the key along the vertical switching axis. A first inclined surface is formed on the key adjacent the horizontal surface with the front of the operator's finger being presented toward the first inclined surface, when the tip thereof is so positioned, for applying force to the key in one direction along the horizontal switching axis responsive to finger contraction. A second inclined surface is formed on the key adjacent the horizontal surface with the rear of the operator's finger being presented toward the second inclined surface, when the tip thereof is so positioned, for applying force to the key in the other direction along the horizontal switching axis responsive to finger extension. In another aspect of the invention, a plurality of such keys are provided on a keyboard for accommodating all of the operator's fingers during data entry operations. In yet another aspect of the invention, data entry of the ten most commonly occuring characters is effected by depressing a selected finger or thumb, data entry of the next ten most commonly occurring characters is effected by contracting a selected finger-or thumb and data entry of the remaining characters is effected by extending a selected finger or thumb. In still another aspect of the invention, the keys on such a keyboard are positioned laterally and vertically so that the horizontal surfaces thereof substantially simultaneously contact the fingertips and thumb of an operator's relaxed cupped hand as it is moved into position for switching the keys.
It is an object of the present invention to provide finger operated switching apparatus for entering data wherein both hand and finger travel are substantially reduced over that required by prior art devices thereby increasing the rate at which an operator may enter data.
It is another object of the invention to provide such an apparatus which is usable by operators having different-sized fingers.